Image enhancement by stochastic homomorphic filtering

Fries, Robert W.; Modestino, J.W.

doi:10.1109/tassp.1979.1163324

Cited by 39 publications

(12 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The improvement is then achieved by the simultaneous compression of the intensity range and the contrast enhancement. This method gave reasonable results and have been used in many applications [12,10,17].…”

Section: Introductionmentioning

confidence: 71%

Reduction of the non-uniform illumination using nonlocal variational models for document image analysis

Bella

Rhabi

Hakim

et al. 2018

Journal of the Franklin Institute

View full text Add to dashboard Cite

In this paper, we investigate two new reflectance and illumination decomposition models based on a nonlocal partial differential equation (PDE) applied to text images. Taking into consideration the higher regularity level of the illumination compared to the reflectance, we propose a nonlocal PDE which deals with repetitive structures and textures that characterize the text image much better compared to the classical local PDEs. The aim of this approach is to use the repetitive features of the reflectance to efficiently extract it from the nonuniform illumination. This idea is motivated by extending the range of application of the nonlocal operators to such problem. Numerical experiments on both grayscale and color text images show the performance and strength of the proposed nonlocal PDE.

show abstract

Section: Introductionmentioning

confidence: 71%

Reduction of the non-uniform illumination using nonlocal variational models for document image analysis

Bella

Rhabi

Hakim

et al. 2018

Journal of the Franklin Institute

View full text Add to dashboard Cite

show abstract

“…This method is used to fix the non-uniform lighting in an image which needs its contrast to be reinforced [7]. It is a frequency filtering technique…”

Section: A Homomorphic Filteringmentioning

confidence: 99%

An Enhancement of Underwater Images using DCP and CLAHE Algorithm

2019

IJEAT

View full text Add to dashboard Cite

The lack of resource requirement in this population world, we are in a position to require another resources. In this regard, ocean is one of our sustenance. It is the exact platform for various applications like, transport, food, energy etc., but still we are surveyed partly at all aspects. One of the main focus of challenge is scattering of light as it penetrate from air to water which presents us with a bluish background while studying the scenery. In this, added to this there is a hazy appearance in the visuals and calls for Image Enhancement techniques. Here, Dark Channel Prior(DCP) is used to remove the haze and noise induced by the bluish environment. However, this proposal of method is also used to increase darkness of the image, Contrast Limited Adaptive Histogram Equalization (CLAHE) is used on the RGB image to enhance the contrast and intensity of the image. Finally, we get visually pleasing result, colour correlation method is carried out. The experimental result shows that a enhanced underwater image from the base image, and mostly useful to analyze and monitoring the underwater images.

show abstract

“…Then, a high-pass filter applied to (2) should attenuate the cloud component and preserve L_Gk(n,m) (or amplify [6]) the high frequencies of the term log [L-aLr(n,m)]. An example of this (long-space) homomorphic filtering is illustrated in Figure 2.…”

Section: B Homomorphic Filteringmentioning

confidence: 99%

“…Since the transfer function of the cloud transmittance was considered to possess only low frequencies, the estimate of this power spectrum was low-pass filtered. Finally, an estimate of MN and MM can be formed from the initial values of the correlation functions associated with the estimates of Spp(u,V) and SNN(u,v) and the relation given by (2).…”

Section: B Homomorphic Filteringmentioning

confidence: 99%

“…In particular, Oppenheim et al [1] and Fries and Modestino [2] have applied homomorphic filtering to enhance images whose fine structure has been obscured by the effects of shadows. The former procedure relies on a deterministic model of shadow formation, while the latter relies on a stochastic model which invokes a random field representation of shadows.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Homomorphic restoration of images degraded by light cloud cover

Peli

Quatieri

ICASSP '84. IEEE International Conference on Acoustics, Speech, and Signal Processing

View full text Add to dashboard Cite

In this paper, we demonstrate the use of adaptive homomorphic filtering in exposing objects under light cloud cover. In particular, the homomorphic filter invoked is space-varying and is parameterized by the local mean level of the degraded image. The local mean serves as an indication of the extent of loca' cloud cover degradation. We show that this adaptive procedure has greater potential than the long-space methods in exposing objects beneath light cloud cover. In addition, adaptive homomorphic filtering compares favorably with an iterative homomorphic enhancement procedure which is an extension of the one-pass nonadaptive homomorphic filter.

show abstract

Image enhancement by stochastic homomorphic filtering

Cited by 39 publications

References 9 publications

Reduction of the non-uniform illumination using nonlocal variational models for document image analysis

Reduction of the non-uniform illumination using nonlocal variational models for document image analysis

An Enhancement of Underwater Images using DCP and CLAHE Algorithm

Homomorphic restoration of images degraded by light cloud cover

Contact Info

Product

Resources

About